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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /arch/x86/lib/hweight.S
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'arch/x86/lib/hweight.S')
-rw-r--r--arch/x86/lib/hweight.S78
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/x86/lib/hweight.S b/arch/x86/lib/hweight.S
new file mode 100644
index 000000000..edbeb3eca
--- /dev/null
+++ b/arch/x86/lib/hweight.S
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/export.h>
+#include <linux/linkage.h>
+#include <linux/objtool.h>
+
+#include <asm/asm.h>
+
+/*
+ * unsigned int __sw_hweight32(unsigned int w)
+ * %rdi: w
+ */
+SYM_FUNC_START(__sw_hweight32)
+ ANNOTATE_NOENDBR
+
+#ifdef CONFIG_X86_64
+ movl %edi, %eax # w
+#endif
+ __ASM_SIZE(push,) %__ASM_REG(dx)
+ movl %eax, %edx # w -> t
+ shrl %edx # t >>= 1
+ andl $0x55555555, %edx # t &= 0x55555555
+ subl %edx, %eax # w -= t
+
+ movl %eax, %edx # w -> t
+ shrl $2, %eax # w_tmp >>= 2
+ andl $0x33333333, %edx # t &= 0x33333333
+ andl $0x33333333, %eax # w_tmp &= 0x33333333
+ addl %edx, %eax # w = w_tmp + t
+
+ movl %eax, %edx # w -> t
+ shrl $4, %edx # t >>= 4
+ addl %edx, %eax # w_tmp += t
+ andl $0x0f0f0f0f, %eax # w_tmp &= 0x0f0f0f0f
+ imull $0x01010101, %eax, %eax # w_tmp *= 0x01010101
+ shrl $24, %eax # w = w_tmp >> 24
+ __ASM_SIZE(pop,) %__ASM_REG(dx)
+ RET
+SYM_FUNC_END(__sw_hweight32)
+EXPORT_SYMBOL(__sw_hweight32)
+
+/*
+ * No 32-bit variant, because it's implemented as an inline wrapper
+ * on top of __arch_hweight32():
+ */
+#ifdef CONFIG_X86_64
+SYM_FUNC_START(__sw_hweight64)
+ ANNOTATE_NOENDBR
+ pushq %rdi
+ pushq %rdx
+
+ movq %rdi, %rdx # w -> t
+ movabsq $0x5555555555555555, %rax
+ shrq %rdx # t >>= 1
+ andq %rdx, %rax # t &= 0x5555555555555555
+ movabsq $0x3333333333333333, %rdx
+ subq %rax, %rdi # w -= t
+
+ movq %rdi, %rax # w -> t
+ shrq $2, %rdi # w_tmp >>= 2
+ andq %rdx, %rax # t &= 0x3333333333333333
+ andq %rdi, %rdx # w_tmp &= 0x3333333333333333
+ addq %rdx, %rax # w = w_tmp + t
+
+ movq %rax, %rdx # w -> t
+ shrq $4, %rdx # t >>= 4
+ addq %rdx, %rax # w_tmp += t
+ movabsq $0x0f0f0f0f0f0f0f0f, %rdx
+ andq %rdx, %rax # w_tmp &= 0x0f0f0f0f0f0f0f0f
+ movabsq $0x0101010101010101, %rdx
+ imulq %rdx, %rax # w_tmp *= 0x0101010101010101
+ shrq $56, %rax # w = w_tmp >> 56
+
+ popq %rdx
+ popq %rdi
+ RET
+SYM_FUNC_END(__sw_hweight64)
+EXPORT_SYMBOL(__sw_hweight64)
+#endif